1. Technical Field of the Invention
The invention relates to telecommunications access techniques, and more particularly, to a system and method for enhancing the access speed and the resource utilization in the local segment of a telecommunications system.
2. Description of Related Art
In most developed countries, wireline telecommunications services are reaching the maturity phase of their lifecycle after over a hundred years of growth. Consequently the revenue growth of wireline service providers is reaching a plateau. Wireline service providers have been eagerly searching for techniques to enhance their revenues. From a marketing viewpoint, wireline providers have available at least three distinct approaches for enhancing their revenues.
The first approach would be to expand the services offered by a wireline provider to new markets and consequently increasing its customer base. This approach works best where a product has a relatively low market penetration. Since the wireline business has reached maturity in the developed world, this approach is not likely to be very successful. The second approach would be to promote an increase in the frequency of use of the wireline service. Since the use of wireline voice services appears to be in a slow-growth phase, this approach too appears to be less than robustly lucrative.
The third approach would be to expand the chargeable use of the wireline access product, e.g., by suggesting various new ways of using the existing product. Most wireline service providers have invested large sums of money (often exceeding several millions of dollars) in setting up their infrastructure. In addition to their capital investments, they typically spend substantial sums (often several millions of dollars each year) in maintaining the copper xe2x80x9ctwisted-pairxe2x80x9d or coaxial cable access lines to their customers. It therefore appears to have a system and method enhancing revenues that adopt this third approach.
Given the current explosion of demand for accessing the Internet, wireline access providers are facing competition in providing Internet access. More and more companies are trying to reach the pool of potential customers through alternative means for providing local access, e.g., by providing wireless access, microwave access, power line access, cable line access, etc. Many of these alternative local access techniques appear to be capable of providing relatively high-speed local access.
A wireline service provider thus needs to be in a strong position to compete with the bandwidth promised by these alternate local access technologies. The current generation of access technologies, e.g., Digital Subscriber Loop (xDSL) and Common Access Protocol (CAP) promise bandwidths of up to 8 Mbps or more. Although these are a significant advances over prior techniques, they still do not capitalize on one of the key realities about the system utilization of a current telephony network: that an average telephone line is in use for only around 8% of the time. Thus, statistically, every telephone line and associated local loop resources are idle for around 21 hours each day. Restated, this means that on average, 92% of local loop transport resources are idle at any given time.
Such unused bandwidth is a perishable resource. Failure to reuse such resources results in a direct loss of potential revenue to the wireline access provider. As a practical matter, the fixed costs of providing wireline access are relatively high while the variable costs associated with reusing the unused bandwidth for providing added bandwidth for another customer are relatively low. Thus the wireline service business is characterized by high fixed costs (xe2x80x9csunk costsxe2x80x9d) and low variable costs (xe2x80x9cmarginal costsxe2x80x9d). It has even been argued that the wireline system is intrinsically a zero marginal cost business. Thus, the profitability of this business is strongly correlated with the system utilization.
In plotting the revenue against costs as a function of system utilization, it can be seen that after reaching the break-even point, all additional revenues contribute directly to the profit of the wireline service provider. Thus, any techniques for increasing the revenue while simultaneously maximizing their available bandwidth utilization is likely to receive quick acceptance from wireline service providers.
Consequently, it is desirable to have a system and method for maximizing the revenue of a wireline service provider while maximizing the use of all available bandwidth over the local loop. It has additionally been desired that the revenue enhancement technique be both simple as well as efficient in its use of network resources. Furthermore, it would be useful for new techniques to work harmoniously with the architecture of traditional Public Switched Telephony Networks (PSTNs) and data networks (e.g., the Internet).
Therefore, it is a primary object of the present invention to provide a system and method for increasing the resource utilization of a telecommunications network in order to permit an increase in access speed without a concomitant increase in resource requirements. It is an additional object of the present invention to improve the operational efficiency of the local loop by digitizing the transmission of voice, video and data signals in the local loop.
The high-speed access technique of the present invention is best understood by considering a simple and common scenario where a LEC (Local Exchange Carrier) Point of Presence (POP) or End Office (EO) services an exemplary medium-sized apartment complex with 100 homes. One end of each of the telephone lines terminates in one of the 100 homes. The other end of each of the telephone lines is connected to the LEC End Office, either directly or through a concentrator (e.g., a Remote Subscriber Stage). When a conventional telephone line is used, it is typically dedicated to the carriage of either voice or data traffic (or both in the case of a phone doubler).
Based on the empirical usage statistics noted above, out of every 100 homes having telephone access, on average, approximately eight to ten homes would be using their telephone line to communicate at any given moment in time, while the remaining 90 or so telephone lines would be idle. A user accessing a data network, such as the Internet, through a modem using the K56flex, x2 or the V.90 protocol would ordinarily be getting a data throughput of around 40-50 Kbps. A xDSL customer can expect a typical download bandwidth of about 6 Mpbs. The system and method of the present invention transforms the exemplary wireline network in such a way that the unutilized or underutilized 90 or so telephone lines are used to carry traffic for one or more of the active users. This can permit the apparent bandwidth to, for example, a single user to be theoretically increased by a factor of approximately 90. If the unused local loop bandwidth is shared evenly by the 8-10 active users, each of these users can obtain a bandwidth improvement of approximately ten-fold.
The system and method of the present invention thus treats the telephone lines to a community as a shared resource, taps the unused bandwidth and harnesses it for Unspecified Bit Rate (UBR) or Available Bit Rate (ABR) traffic as defined by the Asynchronous Transfer Mode (ATM) specifications. The system includes a plurality of home user sites organized in a cluster and connected together in a network, such as a local area network. The system further includes a traffic concentrator having a physical connection to each user site, for receiving communications from a Public Switched Telephony Network (PSTN) and from a data network, such as the Internet. In the system, each PSTN communication and data network/Internet communication identifies a destination user site for receiving the communication. The traffic concentrator transmits the received communication which is deemed delay sensitive and/or is destined to a user site subject to a relatively favorable service level agreement with the telecommunication service provider to the corresponding destination user site over the physical connection corresponding thereto, and transmits the received communication which is delay insensitive and/or destined to a user subject to a relatively less favorable service level agreement to a user site corresponding to an unused physical connection. Each user site includes a traffic deconcentrator for determining if the communication received at the user site is the same as the specific user site to which the communication is destined, and transmitting the communication over the local area network to a distributor upon an affirmative determination that the user site does not match the specific user site to which the communication is destined. The distributor receives the communication from the user site corresponding to the unused physical connection and redirects the communication to the appropriate destination user site.
By transmitting the delay insensitive communication and/or communication destined for a user site which is subject to a less favorable service level agreement between the traffic concentrator and the user sites over unused physical connections, system resource utilization and effective transmission bandwidth are advantageously increased, which thereby increases system resource utilization and system access speed.